The present invention relates to a multi-piece solid golf ball having high trajectory and excellent flight performance by accomplishing low spin amount, high launch angle and high rebound characteristics.
There have been various requirements for physical properties of golf balls, such as flight distance, controllability, shot feel, click sound and the like. Among them, long flight distance always fascinates general golfers and is generally accomplished by increasing coefficient of restitution, reducing spin amount or heightening launch angle. Particularly, a golf ball with high trajectory visually satisfies golfers, and golf ball makers have developed golf balls having high launch angle. In order to heighten launch angle, it is known to the art to soften the whole golf ball, or to adjust hardness distribution such that an outer portion is harder and an inner portion is softer.
However, there is a problem that a golf ball generally has a low coefficient of restitution, which reduces flight distance. In the golf ball adjusting the hardness distribution that the outer portion is harder and the inner portion is softer, there is another problem that the spin amount is low, but the initial velocity is low, which reduces flight distance, when compared with a golf ball having an even hardness distribution.
A main object of the present invention is to provide a multi-piece solid golf ball having high trajectory and excellent flight performance by accomplishing low spin amount, high launch angle and high rebound characteristics.
According to the present invention, the object described above has been accomplished by forming a multi-piece solid golf ball comprising a core composed of an inner layer core placed in the innermost layer and at least one layer of an outer layer core formed on the inner layer, and a cover formed on the core, in which the lowest elastic modulus layer having the lowest elastic modulus is placed in the core, and an elastic modulus of the inner layer core, an elastic modulus difference between the inner layer core and the lowest elastic modulus layer, a thickness and position of the lowest elastic modulus layer, and a diameter of the core are adjusted to a specified range. The present invention materializes low spin amount, high launch angle and high rebound characteristics, and provides a multi-piece solid golf ball having high trajectory and excellent flight performance.
This object as well as other objects and advantages of the present invention will become apparent to those skilled in the art from the following description with reference to the accompanying drawings.